For sale Maxon AD-900 with two NOS Panasonic MN3005 BBD chips. In excellent condition. Sounds absolutely beautiful.
The crappy, cheap electrolytic capacitor were all changed to polyester WIMA caps and audio grade electrolytic Nichicon caps. The opamp was upgraded to analog devices OP275. I can include the stock JRC4558D as well.
The pedal is calibrated to perfection. I can send an audio sample of the pedal upon request.